基于galectin-3介导的炎症信号通路探讨尖叶假龙胆及其有效成分逆转心肌纤维化的分子机制

Galectin 3 is a novel prognostic marker of myocardial fibrosis (MF) and remodeling. It is potential therapeutic targets for MF. In Mongolian, Gentianella acuta was used to treat arrhythmia and other heart diseases for a long time, and the effect is significant. It is presumed that Gentianella acuta should have anti- MF. Our preliminary study found that Gentianella acuta could significantly inhibit fibrosis after myocardial infarction and reduced levels of the protein galectin-3. On the Basis of previous research results, we will explore the mechanism of Gentianella acuta inhibiting MF by inflammatory signaling pathways , from the overall, cell, gene level. The study was designed to investigate the effect of galectin-3 on myocardial fibrotic formation using shRNA gene knockout technology， Further to explore the mechanism is whether or not to affect TGF-β and NF-κB inflammation signaling pathway and interactions between galectin-3 and TGF -β signals in MF。The objective of the present study is to clarify inflammatory reaction mechanism, of galectin -3 involved in MF, looking for potential targets for prevention and control of MF and new form of therapy, to provide basic pharmacological data for Gentianella acuta anti-MF.

Galectin-3是心肌纤维化和心肌重构的生物标记物，为逆转心肌纤维化的潜在治疗靶点。蒙药尖叶假龙胆具有清热利湿功效，在民间长期用于治疗心脏病且效果显著。我们前期工作中已证实尖叶假龙胆可以降低心肌组织中Galectin-3水平，显著抑制心肌梗死后间质纤维化。推测尖叶假龙胆可通过Galectin-3信号通路发挥其抗心肌纤维化的作用。本研究在前期研究结果的基础上，从整体、细胞、基因水平上，以炎症信号通路为切入点，探讨蒙药尖叶假龙胆及其有效成分抑制心肌纤维化的作用机制和干预靶点。利用分子生物学手段敲除或过表达Galectin-3，观察心肌组织中TGF-β和NF-κB炎症通路的变化，探讨Galectin-3与TGF-β信号之间的cross-talk，阐明Galectin-3参与心肌纤维化的炎症反应机制，寻找心肌纤维化的潜在治疗靶点和新的防治策略，为尖叶假龙胆用于防治心肌纤维化提供药理学依据。

心血管疾病成为全球的主要死因，心肌纤维化是多种心血管疾病发展的共同病理学基础，是心室重构持续发展导致心功能不断恶化的关键因素，预防和逆转心肌纤维化已成为心血管疾病的主要治疗目标。蒙药尖叶假龙胆（Gentianella acuta，G.acuta）具有清热利湿功效，在民间长期用于治疗心脏病且效果显著。本研究以半乳糖凝集素-3（galectin-3，Gal-3）炎症信号为切入点，探讨G.acuta及其成分bellidifolin抑制心肌纤维化的作用靶点。研究结果显示，（1）G.acuta可减低MDA，升高SOD和GSH水平，下调Gal-3、NF-κB、TGF-β1和CTGF表达，减轻ISO 诱导大鼠心肌纤维化。（2）G.acuta抑制TGF-β受体I/II的磷酸化，下调Smad4的表达和Smad2/3d的磷酸化，阻断TGF-β1/Smads信号通路活化抑制心肌纤维化。（3）MCP特异性阻断Gal-3，可抑制TLR4/MyD88/NF-κB信号通路的激活，减轻心肌纤维化。（4）G.acuta抑制Gal-3/TLR4/MyD88/NF-κB炎症信号通路，预防ISO诱导急性心肌损伤。（5）Bellidifolin抑制TGF-β受体I/II的磷酸化活化，阻断TGF-β1/Smads及TGF-β1/p38信号活化，抑制心肌成纤维细胞活化和减轻ISO诱导的小鼠心肌纤维化。研究结果证实，Gal-3在心肌纤维化中起着关键作用。G.acuta和bellidifolin下调Gal-3，干预TLR4//NF-κB炎症信号以及TGF-β经典与非经典型信号通路, 抑制心肌成纤维细胞活化，减轻ISO诱导的急性心肌损伤和纤维化，改善心脏功能。本研究为心肌纤维化的临床防治提供了新思路和新靶点，为G.acuta临床应用和新药开发提供理论基础和实验依据。